1. Field of the Invention
The present invention relates to an inspection apparatus, a control method of the inspection apparatus, and a storage medium.
2. Description of the Related Art
Conventionally, a commercial printing industry issues printed matters through procedures, such as receiving manuscript, design or layout, comprehensive layout (presentation for a printed output), proofreading (layout correction or color correction), outputting proof (proof printing), block copy preparation, printing, post-processing, and delivery. In the above described procedures, the commercial printing industry mainly uses a large-scaled printing apparatus such as an offset plate printing apparatus, and needs block copy preparation. However, a block copy is created once, correction thereof is not easy, and it is enormously disadvantage in costs. Careful proofing (layout check or color check) is required, and a certain period for creating the printed matter is necessary. On the other hand, increase in speed and quality of an electrophotographic image forming apparatus (printing apparatus) or an inkjet image forming apparatus is remarkable. Then, a market appears to handle a job called a print on demand (hereinafter, referred to as a POD) with a lot relatively smaller than a job handled by the printing apparatus without using a large-scaled apparatus for short delivery, to compete against the commercial printing industry.
The POD market realizes digital printing using electronic data with a digital image forming apparatus such as a digital copying machine or a digital multifunction peripheral, and the level is closer to that of the printing industry to some degree by using a computer. In the printing industry or the POD market, inspection operation for checking whether a printed matter to be delivered to a client has no defect is not automated, and an operator manually checks and inspects the printed matter in the current situation. However, in the case of a printed matter having several hundreds pages, inspection of all the pages in detailed requires enormous time and labor. Rough inspection operation such as partial pick-up from the printed matter may cause a problem such as an oversight of small printing errors, misprints, and dirt on paper. In order to solve such a problem, a technique for automating the inspection operation of the printed matter is demanded. A technique for automating the inspection operation is known to inspect a printed matter by comparing an inspection image for inspecting the printed matter with an image obtained by capturing the printed matter (refer to Japanese Patent Application Laid-Open No. 11-39492).
With the technique, in a step of obtaining an image by capturing a printed matter, a skewed image may be captured and obtained as a result of skewing paper or misregistration of paper in a lateral direction during conveyance of the printed matter. If the skewed image is compared with the inspection image, an image originally correctly printed can be determined as a print defect and inspection efficiency can deteriorate. Accordingly, such a technique is known to detect a skew amount of paper, correct a captured image based on the detected skew amount, and compare the corrected image with the inspection image (refer to Japanese Patent Application Laid-Open No. 6-266892).
However, with the technique for detecting the skew amount, correcting the captured image based on the detected skew amount, and correcting the image, misregistration of a print position on paper is not corrected. Therefore, a printed matter which is normally determined as an appropriate product by a user may be determined as a print defect and the inspection efficiency thus deteriorates. When inspection of the printed matter is performed after correcting the misregistration of the print position on paper, the image is corrected total twice. With the current technology, the image correction takes a long time and the inspection efficiency consequently becomes down.